Population dynamics of land snails (Mollusca: Gastropoda) in Katana region, west coastline of Lake Kivu, Eastern of Democratic Republic of Congo

Monthly and seasonal fluctuations in densities of land snails were recorded in four different sites (forest, fallow, cultivated area and wetland) in Katana region during the period of January to December 2013. The aim of this survey is to study the population dynamics of the land snails of the Katana region considering some geo-physical factors (rainfall, relative humidity and temperature) in different habitats. The study revealed the occurrence of 31 species of land snails belonging to 9 families of class Gasteropoda. The land snail species and their total catch were: Limicolaria laeta medjensis (225 specimens), Limicolaria distincta (195 specimens), Ataxon faradjense (159 specimens), Achatina achatina (147 specimens), Lehmannia valentiana (118 specimens), Achatina tincta (108 specimens), Curvella bathytoma (98 specimens), Trichotoxon pardus (78 specimens), Trichotoxon ruwenzoriense (75 specimens), Burtoa nilotica emini (72 specimens), Nothapalus paucispira xanthophaes (69 specimens), Trichotoxon maculatum perforatum (68 specimens) ,Pachnodus rutshuruensis (66 specimens), Gymnarion aloysii-sabaudiae (65 specimens), Mesafricarion putzeysi (64 specimens), Cerastus bequaerti (60 specimens), Gullela pupa ituriensis (58 specimens), Helixarion insularis (58 specimens), Bukobia cockerelli (56 specimens), Mesafricarion maculifer pilsbry (56 specimens), Perideriopsis fallsensis (56 specimens), Achatina fulica (54 specimens), Burtoa nilotica obliqua (52 specimens), Pleuroprocta silvatica (52 specimens), Pseudoglessula walikalensis (35 specimens), Achatina osborni(31 specimens), Loevicaulis schnitzleri (17 specimens), Subulinuscus ruwenzorensis (6 specimens), Homorus amputatus (4 specimens) , Theba pisana (4 specimens) and Arion rufus (3 specimens) in a descending order. The densities of the recorded land snails varied seasonally and the general seasonal peak was recorded during rainy while the lowest density observed during dry. Ecological factors which may influence the distribution or variation of the recorded land snails were also determined (temperature, relative humidity and rainfall). We remarked that the rainfall and the relative humidity were the two main ecological factors which influence the distribution or variation of the land snails in Katana region.